684 jobs found

Kotlin Developer Contract Summary Box: Location: On-Site Contract Length: 3 months Day Rate / Pay: £500.00 IR35 Status: Outside IR35 Start Date: 17/07/2026 The Kotlin Developer contract involves building and maintaining backend integrations for a healthcare-focused AI platform, working within a team to deliver scalable and secure systems. The role requires collaboration with various stakeholders including product managers, engineering teams, and external partners. This is a remote working environment, but the location requirement is on-site, with no relocation offered. Key Responsibilities Design, develop, and maintain integrations between the platform and third-party healthcare systems. Build scalable, secure backend services and APIs using Kotlin. Take ownership of integration projects from architecture to deployment and improvement. Develop data models and architecture to support healthcare workflows. Collaborate with stakeholders to deliver high-quality solutions. Contribute to engineering standards, documentation, and performance improvements. Requirements On-site location with the right to work in the designated country. No relocation assistance provided. Several years of professional backend software engineering experience. Strong commercial experience in Kotlin development. Knowledge of Kotlin Coroutines and asynchronous programming. Experience designing and maintaining RESTful and/or GraphQL APIs. Experience integrating with third-party systems and external APIs. Strong understanding of scalable backend architecture and API design principles. Experience designing data models for complex business domains. Business-level English proficiency (C1 or equivalent). Willingness to travel occasionally to the UK or US as required.

Gravitas Group is seeking a Kotlin Developer for an on-site contract in the UK. You will join a healthcare AI platform team to build and maintain backend integrations, APIs, and scalable services in collaboration with product managers and engineering peers. The role emphasizes Kotlin development, RESTful and GraphQL API design, and data modeling to support complex healthcare workflows. Remote work is not offered; occasional travel may be required.

A leading streaming platform is looking for a Senior Software Engineer (Backend) in Manchester. The role involves designing scalable backend services, maintaining robust APIs, and working collaboratively across teams. Ideal candidates will have experience with Java, Python, Docker, Kubernetes, and a degree in computer science or a related field. This position offers comprehensive benefits that support employee well-being and a dynamic work culture focused on innovation and collaboration.

Senior Software Engineer, Mobile Cloud - Manchester, United Kingdom Teamwork makes the stream work. Roku is changing how the world watches TV Roku is the TV streaming platform in the U.S., Canada, and Mexico, and we've set our sights on powering every television in the world. Roku pioneered streaming to the TV. Our mission is to be the TV streaming platform that connects the entire TV ecosystem. We connect consumers to the content they love, enable content publishers to build and monetize large audiences, and provide advertisers unique capabilities to engage consumers. From your first day at Roku, you'll make a valuable - and valued - contribution. We're a fast-growing public company where no one is a bystander. We offer you the opportunity to delight millions of TV streamers around the world while gaining meaningful experience across a variety of disciplines. About The Role Millions of people around the globe rely on our products every day because they "just work," seamlessly integrating into users' lives. Achieving that intuitive user experience isn't accidental-it's crafted by dedicated teams committed to simplicity and clarity. We're seeking a Senior Software Engineer (Backend) who excels at building scalable, reliable services. Our Roku Mobile Backend team designs and implements robust backend services powering our mobile apps, ensuring optimal performance, low latency, and seamless scalability. If you're passionate about backend engineering and thrive on delivering innovative mobile-cloud solutions, we'd love for you to join us. We collaborate closely with client-side engineers, other backend teams, and product management, iterating rapidly-from prototypes and A/B tests through to global releases. About The Team You will be joining a talented, high-performant backend team with a history of delivering quality products. We are looking for someone who can help us keep up this pace and continue delivering high-quality services as we grow. What You'll Do Design and develop scalable, high-performance backend services powering Roku mobile apps. Build and maintain robust APIs and microservices integrating seamlessly with mobile clients and cloud infrastructure. Develop and optimize a highly efficient auto-scaling platform utilizing Docker containers and Kubernetes orchestration. Ensure reliability and uptime of backend systems through comprehensive monitoring, testing, and automation. Troubleshoot and resolve complex technical challenges within production environments swiftly and effectively. Continuously assess and implement emerging technologies to boost system performance and developer productivity. Collaborate cross-functionally with product, design, frontend, and other backend teams, driving seamless integration, consistency, and exceptional user experiences. Expertise of backend software engineering Bachelor's or master's degree in computer science, engineering, or related field (or equivalent experience). Strong proficiency in backend languages like Java or Python. Proficiency in using AI tools (e.g., GitHub Copilot, ChatGPT) and experience with prompt engineering Demonstrable experience designing, building, and maintaining RESTful APIs, utilizing HTTPS, JSON, and WebSocket. Hands-on expertise developing and operating large-scale cloud services using Docker and Kubernetes. Proven capability in writing and maintaining comprehensive automated unit and integration tests. Deep understanding of distributed systems, microservices architecture, and database technologies. Familiarity with CI/CD pipelines, Test-Driven Development (TDD), and automation frameworks. Skilled in production system monitoring, troubleshooting, and issue resolution. Exceptional problem-solving skills focused on delivering efficient, practical solutions. Strong communication abilities, adept at working effectively with both technical and non-technical stakeholders. A proactive and driven mindset, capable of independently managing tasks from inception to completion. Ability to thrive in a dynamic, fast-paced environment, adeptly managing shifting priorities. Roku is committed to offering a diverse range of benefits as part of our compensation package to support our employees and their families. Our comprehensive benefits include global access to mental health and financial wellness support and resources. Local benefits include statutory and voluntary benefits which may include healthcare (medical, dental, and vision), life, accident, disability, commuter, and retirement options (401(k)/pension). Our employees can take time off work for vacation and other personal reasons to balance their evolving work and life needs. It's important to note that not every benefit is available in all locations or for every role. For details specific to your location, please consult with your recruiter. The Roku Culture Roku is a great place for people who want to work in a fast-paced environment where everyone is focused on the company's success rather than their own. We try to surround ourselves with people who are great at their jobs, who are easy to work with, and who keep their egos in check. We appreciate a sense of humor. We believe a fewer number of very talented folks can do more for less cost than a larger number of less talented teams. We're independent thinkers with big ideas who act boldly, move fast and accomplish extraordinary things through collaboration and trust. In short, at Roku you'll be part of a company that's changing how the world watches TV. We have a unique culture that we are proud of. We think of ourselves primarily as problem-solvers, which itself is a two-part idea. We come up with the solution, but the solution isn't real until it is built and delivered to the customer. That penchant for action gives us a pragmatic approach to innovation, one that has served us well since 2002. By providing your information, you acknowledge that you have read our Applicant Privacy Notice and authorize Roku to process your data subject to those terms.

About this role Capital One's mission is to change banking for good by bringing humanity, ingenuity and simplicity to banking. Sitting at the core of such values is our Software Engineering department whose primary role is to be an enabler of our ambitions. Capital One is looking for a Lead Software Development Engineer to join a backend team, based in our Nottingham office on a hybrid basis. Our Engineers are people who lead by example, build strong and valuable relationships and have the confidence to influence at all levels. We are proud of who we are and what we do and want you to join us at this particularly exciting time at Capital One. What you'll do You will lead a team or cross functional squad in the delivery of complex and ambiguous projects that support a broader business outcome. You will take end to end responsibility for technical design, implementation, and operational considerations. Collaborate with engineers, architects, product owners, and stakeholders to ensure successful project outcomes. You will play a crucial role in supporting the elevation of engineering enablement, excellence, and experience across the broader engineering community. You will collaborate and contribute to the development and dissemination of standardised and sustainable best practices, tools, patterns, and frameworks that enhance the productivity and quality of engineering efforts business wide. Your focus is on a major portion of existing or new team software (e.g., significant component, set of features, mid size application or service). You'll work to achieve the goals and vision shared by Product Management and your Tribe Leadership. Innovate within your team, initiative area and contribute within your technical domain. What we're looking for Proven experience in technical leadership, including leading a team or cross functional squad. Proven experience working in both backend services and mobile technologies. Exceptional programming skills and knowledge of building APIs using modern OO languages preferably Java, SOLID principles, SOA, HTTP and REST. Experience with AWS and strong understanding of cloud based development. Extensive, demonstrable knowledge of designing architectures that are secure and perform at scale. You're able to effectively communicate and work collaboratively across engineering to maximise inner sourcing opportunities and reduce waste. Proven experience ability to deliver high quality applications at scale. An advocate for quality and the ability to support the team, leveraging approaches such as Pair Programming, TDD and BDD. Where and how you'll work This is a permanent position and will be based in our Nottingham office. We have a hybrid working model which gives you flexibility to work from our offices and from home. We're big on collaboration and connection, so you'll be based in our Nottingham office 3 days a week on Tuesdays, Wednesdays and Thursdays. What's in it for you Bring us all this and you'll be rewarded with a role contributing to the product roadmap for an organisation committed to transformation. We're continuing our journey into the public cloud and have problems of scale, security, availability and performance for you to help solve. We love continuous learning and that's why we give you 10% of your time to work on cutting edge innovative projects that shape the way we will work in the future. We offer high performers strong and diverse career progression, investing heavily in developing great people through our Capital One University training programmes (and appropriate external providers). Immediate access to our core benefits including pension scheme, bonus, generous holiday entitlement and private medical insurance - with flexible benefits available including season ticket loans, cycle to work scheme and enhanced parental leave. Open plan workspaces and facilities designed to inspire and support you. Our Nottingham head office has a fully serviced gym, subsidised restaurant, mindfulness and music rooms. In London, you can heighten your mood with a run on our rooftop running track or an espresso at the Workshop Coffee cafe.

Senior Software Engineer II - Contacts Team - Java Full-time Compensation: GBP 105,000 - GBP 130,000 - yearly Wise is a global technology company, building the best way to move and manage the world's money. Min fees. Max ease. Full speed. Whether people and businesses are sending money to another country, spending abroad, or making and receiving international payments, Wise is on a mission to make their lives easier and save them money. As part of our team, you will be helping us create an entirely new network for the world's money. For everyone, everywhere. The Contacts team is a core team at Wise, dedicated to making adding, finding, and managing your recipients as easy as possible. We own this experience end-to-end: from the scalable platform securing tens of millions of bank accounts customers send to, to the intelligent search algorithms and local integrations (like Pix) that power discovery, all the way to the customer-facing screens where users interact with their counterparties. The team is integral to Wise's day-to-day operations - if our services go down, Wise goes down. How we work We work in an agile fashion, with engineers closely collaborating with designers, the product manager, and the analyst. The team operates across our Tallinn and London offices. What will you be working on? You will be part of an autonomous team, driving the technical vision for the backend solution powering the recipient's user experience. You will help us scale-up and build a world class recipient management product. What do you need? We are fully aware that it is uncommon for a candidate to have all skills required and we fully support everyone in learning new skills with us. So if you have some of those listed below and are eager to learn more, we do want to hear from you! You get things done You have experience working with large scale distributed systems You have years of Java 8+ knowledge You have experience working with relational and non-relational databases, query optimisation and designing schemas You have a strong product mindset and passion for customer experience, you prioritise work with the customers in mind and make data-driven decisions to fix customer pain-points You enjoy collaborating with others and bringing people together to solve a problem You have experience in designing, deploying and maintaining clean RESTful APIs You believe in and follow best coding practices, code reviews and open feedback You enjoy writing testable code and believe in Test Driven Development Nice to have You have experience with Spring boot You have worked with BFFs (Backend-for-Frontends) For everyone, everywhere. We're people building money without borders - without judgement or prejudice, too. We believe teams are strongest when they are diverse, equitable and inclusive. We're proud to have a truly international team, and we celebrate our differences. Inclusive teams help us live our values and make sure every Wiser feels respected, empowered to contribute towards our mission and able to progress in their careers. If you want to find out more about what it's like to work at Wise visitWise.Jobs .

SLAMcore is seeking a Senior Staff Software Engineer based in England. In this remote role, you will focus on improving backend stability and leading projects from client applications to backend services. The ideal candidate has over 10 years of experience in software engineering, previous leadership experience in high-performing teams, and a strong understanding of enterprise-level SaaS products. The position offers a competitive salary starting at EUR/GBP/CHF 160,000 plus stock options, along with 25 days of leave and local holidays.

About the company Our mission is that "Any financial application can onboard any user, anywhere in the world, in 1 click." Transak provides onboarding to financial applications through authentication, KYC, risk checks, and fiat on/off ramps. This is a next generation of infrastructure for the next generation of financial applications that are built on blockchain and stablecoin rails. Our API and widget-based solutions are used by top partners like MetaMask, Coinbase, Ledger, and Trust Wallet to enable seamless onboarding of over 10 million users across over 450 active applications. We have raised over $37M from top-tier investors including Consensys, Tether, and Animoca Brands About the role Transak's Fiat/Payments team builds and operates the rails that move money between traditional banking systems and crypto - ACH, SEPA, Faster Payments, wires, virtual accounts, and card rails. As an SDE 3, you will own critical, high-throughput payment microservices end-to-end: design, build, scale, and operate systems that move real money for users across multiple currencies and jurisdictions, with US,UK/EU regulatory and global banking-partner requirements as a core part of the job. This is a senior individual-contributor role calibrated against SDE 3 / Senior Engineer, driving architecture decisions, mentoring engineers, and being the go-to owner for a payments domain, while staying hands-on in code daily. Key Responsibilities Payment Systems Ownership & Architecture Own payment microservices end-to-end - design, build, deploy, and operate Node.js services (orders, payment, reconciliation, virtual accounts, payout orchestration) handling real-time financial transactions at scale. Design for correctness and failure: idempotent, retry-safe, reconciliable systems where every transaction is traceable, auditable, and recoverable (partial failures, webhook replays, duplicate detection, distributed state machines). Architect for scale and resilience across a distributed microservices architecture; make service-boundary and build-vs-buy decisions; address root causes rather than symptoms. Banking & Partner Integrations Drive integrations with banking and payment partners (e.g. banking and card providers / risk providers) - API contracts, webhook handling, sandbox-to-production rollout, and reconciliation logic across multiple rails (ACH, SEPA, Faster Payments, wires). Work with Risk, Compliance on KYC, AML, and fraud-control touchpoints in the payment flow. Infrastructure, CI/CD & Operations Build and maintain CI/CD pipelines (Jenkins) - automated testing, blue/green or canary deployments, and rollback strategies for services that cannot tolerate downtime or data loss. Operate infrastructure on AWS (ECS/EKS, Lambda, SQS/SNS, RDS, CloudWatch); contribute to infra-as-code, monitoring, alerting, and on-call runbooks for payment-critical systems. Optimize the data layer: schema design and query performance in MongoDB, caching and rate-limiting strategies with Redis, and safe migration patterns for high-volume transactional collections. Participate in on-call for payment-critical services, including incident response and postmortems. Technical Leadership & Collaboration Lead technical roadmaps - break down large, ambiguous payments initiatives into shippable milestones; write design docs/RFCs; drive consensus across Engineering, Product, Risk, and Operations. Mentor and raise the bar - review code and designs, coach mid-level engineers, and help hire and grow the team. Uphold security and compliance best practices for handling PII/financial data in a regulated, PCI-DSS-adjacent environment. What We're Looking For 6+ years of professional software engineering experience, with a significant portion building backend/distributed systems; prior experience in fintech, payments, on-and-offramp provider, or banking infrastructure strongly preferred. Strong hands-on expertise in Node.js (TypeScript preferred) for performant, production-grade backend services. Deep experience with MongoDB - schema design, aggregation pipelines, indexing strategy, and performance tuning at scale. Proficiency with Redis - caching, distributed locks, rate limiting, and pub/sub patterns. Proven experience designing and operating microservices architectures, including inter-service communication (REST/gRPC/event-driven via SQS/Kafka,ELK,New relic, Mixpanel), service discovery, and API contract design. Solid understanding of CI/CD pipelines, with hands-on experience using Jenkins (pipeline-as-code, multi-stage builds, automated test gates). Working knowledge of AWS infrastructure - ECS/EKS/Lambda, VPC networking basics, IAM, S3, RDS, CloudWatch; infra-as-code (Terraform/CloudFormation) is a plus. Strong grasp of distributed systems fundamentals: idempotency, eventual consistency, retries/backoff, circuit breaking, and failure isolation. Track record of owning a service or domain end-to-end in production, including on-call responsibility. Excellent written communication - comfortable authoring design docs/RFCs and explaining trade-offs to engineers and non-technical stakeholders (Risk, Ops, external partners). Nice-To-Haves Experience with payment rails (ACH, SEPA, Faster Payments, SWIFT/wires) or card processing. Familiarity with banking partner integrations, webhook-driven reconciliation, or ledger/double-entry accounting systems. Exposure to KYC/AML/fraud tooling. Experience at a fintech/crypto-native company, payments processor, or Big Tech payments org. Prior experience operating in a regulated environment (FCA, EMI/PI licensing context), given the UK/EU banking scope of this role.

Smart Working Solutions is seeking a Lead Data Engineer to architect and scale the data infrastructure powering a cutting-edge AI assistant for property management. You will own real-time data pipelines, vector databases and ML data workflows, shaping architecture and data team culture as the first senior data hire. You will collaborate with AI, backend, and product teams to ensure scalable, reliable data platforms and guide long-term data strategy across global teams.